“The numbers of people contracting the disease appears to have now peaked. It is therefore an appropriate time for the members of the incident management team to answer questions about the handling of the outbreak and progress in identifying the source.

“Two people have tragically died as a result of this disease. Where we can, we must learn lessons from this case, which will be a key part of the committee’s questioning.”

The committee has called members of the incident management team which is managing the outbreak to appear in front of it next Tuesday.

Witnesses will include Pam Waldron, HSE director for Scotland; Dr Alison McCallum, NHS Lothian’s director of public health and health policy; Dr Duncan McCormick, NHS Lothian consultant in public health; Colin Sibbald, food health and safety manager at the city council; and Dr Jim McMenamin, consultant epidemiologist in the respiratory team at Health Protection Scotland.

SNP MSP Bob Doris, deputy convener of the committee, said: “The committee was keen to let those handling the outbreak to get on with their jobs and focus on dealing with this serious public health issue.

“With the outbreak now under control, the committee is pleased the incident management team is willing to appear in front of MSPs. The evidence session will allow the health committee to play a constructive role scrutinising the management of the outbreak. We are not calling into question any specific actions but rather assisting in promoting continuous improvement in how such incidents are managed.”

The Scottish Government said six patients were being treated in intensive care – one fewer than before – and 18 on general wards, while 19 cases were being treated in the community, 39 had been discharged from hospital and two people had died. Seven cases are being treated outwith the NHS Lothian area.

Health Secretary Nicola Sturgeon said: “I am pleased to see a reduction in the number of people in intensive care. I would like to thank the hard-working staff at NHS Lothian who are continuing to provide the very best treatment to the remaining six individuals who are critically ill.”

Dr Duncan McCormick said: “We are encouraged to see that the numbers of patients with legionnaires’ disease in Lothian remains unchanged. This is in line with our prediction.

“We will continue to monitor all of the services in Lothian, but overall the numbers of people seeking treatment or with concerns continue to fall.”